It is known that, for various reasons, there is an increasing interest in the market of “smart devices”, which assist the user in handling the respective device correctly. A “smart toothbrush”, for example, could unburden parents from having to survey whether their children are brushing their teeth compliantly. For example, humans should brush their teeth regularly from a timing and frequency point of view and correctly in terms of the right brushing technique and coverage such as twice a day for 2 minutes with, at each time, covering all teeth and brushing the teeth evenly distributed across the 2 minutes.
Accordingly, there is a need for concepts allowing the provision of personal hygienic devices, such as toothbrushes, shavers or the like, with smart functions. However, in order to find enough acceptance in the market, the concept should allow for an easy and inexpensive implementation. Personal hygienic devices such as a toothbrush are occluded to a large extent when viewing the user during treatment using the respective personal hygienic devices what causes problems in video based tracking systems like in [13]. Moreover, location determination systems which may be built into personal hygienic device are either expensive or do not determine the location of the respective personal hygienic device sufficiently so as to determine the head portion of the user currently treated using the device.
Naturally, the needs and demands just-outlined also occur with respect to other personal hygiene devices that are used on other parts of the body—not only head or face.
Accordingly, there is a need for a concept for determining a body portion of a user treated by the user using a personal hygienic device, wherein the concept allows for an inexpensive implementation. The knowledge about the head portion treated by the user may, for example, allow for assisting the user in performing the treatment.